视网膜色素上皮、Bruch膜及脉络膜的老年性黄斑变性改变

目的研究并定量分析视网膜色素上皮(retinalpigment epithelium,RPE)、Bruch膜和脉络膜的老年性改变及在老年黄斑变性眼的改变。方法应用改良Masson三色组织染色法及电脑图像分析软件,对36例不同龄正常眼及6例老年黄斑变性(age—related macular degenera—tion,ARMD)眼的RPE数量和形态、Bruch膜的厚度和脉络膜毛细血管的密度及脉络膜厚度进行定量分析研究及讨论。结果RPE老年性形态改变包括数量的减少及细胞高度的增加伴有Bruch膜增厚(老年性黄斑变性);但脉络膜毛细血管密度及脉络膜的厚度与年龄未见明显的关系。ARMD眼主要表现为RPE形态明显改变及基底膜线样沉着物形成,Bruch膜增厚。结论RPE以及Bruch膜的改变可能是早期和基础性的老年性改变,其进一步的变化可能导致脉络膜及视网膜的损害。     

Patterns of increased in vivo fundus autofluorescence in the junctional zone of geographic atrophy of the retinal pigment epithelium associated with age-related macular degeneration

Purpose: To determine in vivo lipofuscin (LF)-induced topographic variations of fundus autofluorescence in eyes with geographic atrophy (GA) of the retinal pigment epithelium (RPE) associated with age-related macular degeneration (ARMD). · Methods: Fundus autofluorescence was examined with a confocal scanning laser ophthalmoscope (Heidelberg Retina Angiograph) after excitation with an argon laser (488 nm) and detection of the emitted light above 500 nm. Fifty-seven eyes of 38 patients with uni- or multifocal GA associated with ARMD were studied. The findings were compared with 43 eyes with GA secondary to other etiologies, including juvenile macular dystrophies. · Results: An increased autofluorescence outside the GA was observed in 47 (82.5%) of 57 eyes with GA associated with ARMD in contrast to 4 (9.3%) of 43 eyes with GA of other causes (P<0.001). Three different patterns were noted: a continuous band at the margin with variable peripheral extension in 36 eyes (76.6%), a diffusely increased autofluorescence at the entire posterior pole in 6 eyes (12.8%), and small focal spots of increased autofluorescence in the junctional zone in 3 eyes (6.4%). Of 19 patients with bilateral GA, 17 (89.5%) had an identical pattern in both eyes. · Conclusions: The different patterns of autofluorescence in the presence of GA associated with ARMD may reflect variable forms of reactive changes in the surrounding RPE cells, and may indicate the extend of compromised RPE secondary to ageing changes in the outer retina, Bruch’s membrane and choriocapillaris. Since GA spreads over time, increased LF accumulation in the junctional zone may precede cell death and may, therefore, be of prognostic value. Knowledge of the topographic variation in LF accumulation is important because heterogeneity may reflect underlying differences in cell kinetics, metabolism and biochemistry.     

miR-146在湿性ARMD中抑制IL-6表达的研究

目的:探讨miR-146表达与眼球衰老的相关性,以及年龄相关性黄斑变性(age-related macular degeneration,ARMD)发生过程中miR-146与炎症因子表达的相关性及其可能的机制.方法:分离鼠龄为2~24mo的小鼠RPE,采用qRT-PCR的方法检测RPE中miR-146 a/b和IL-6 mRNA的表达水平.检测来自于ARMD患者眼球中miR-146 a及IL-6 mRNA的表达水平.在ARPE-19细胞系中检测miR-146 a过表达对IL-6基因表达水平的影响.结果:miR-146的表达在自然衰老的小鼠RPE中与年龄呈现正相关,而IL-6无变化.在ARMD患者中,miR-146 a mRNA表达水平下降,IL-6 mRNA表达水平上升.在人ARPE-19细胞中的实验表明,miR-146 a过表达抑制了由TNF-α所诱导的IL-6的表达.结论:在湿性ARMD中,miR-146a与IL-6 mRNA表达水平有可能与ARMD的发生呈相关性,暗示IL-6和miR46 a有可能作为生物分子标志物在未来的ARMD诊断中发挥作用.     

Retinal angiomatous proliferation in age-related macular degeneration

BACKGROUND: Angiomatous proliferation in ARMD originates from the retina and extends into the subretinal space. Retinal angiomatous proliferation (RAP) is diagnosed with angiography. This study investigates the characteristics of RAP in optical coherence tomography (OCT) and correlates them with clinical and fluorescein angiographic findings. METHODS: 327 consecutive patients with age-related macular degeneration (ARMD) were retrospectively examined using a standardised protocol. The protocol included best corrected visual acuity (BCVA), binocular ophthalmoscopy, fundus photography, fluorescein angiography (FAG) and OCT. The OCT and angiographic findings were graded in 3 RAP stages. RESULTS: 32 of 327 (9.79 %) patients (45 eyes) had RAP. The age ranged from 56 to 90 years (median: 79 years). 9 eyes presented RAP stage I, 23 stage II and 13 stage III. BCVA ranged from 0.01 to 0.7 (median: 0.2). OCT foveal minimum was 136 to 722 microns (median: 327). 33 (73 %) eyes showed a detachment of retinal pigment epithelium (RPE). Macular oedema was found in 43 (96 %) eyes. Cystoid macular oedema was seen in 36 (80 %) eyes. In stage II, 22 eyes (96 %) showed an RPE detachment, in stage III 11 eyes (85 %). 11 (85 %) eyes in stage III showed retinal-choroidal anastomosis. CONCLUSIONS: RAP was found in 9.79 % of the patients with ARMD. The OCT is helpful in detection of RPE detachment, macular oedema and cystoid changes in RAP. RAP and retinal-choroidal anastomosis should be identified because of the possibly poor prognosis.     

Surgical management of subfoveal choroidal neovascularization.

BACKGROUND: Subfoveal choroidal neovascularization (CNV) usually is associated with a poor visual prognosis. Laser photocoagulation of certain subfoveal membranes secondary to age-related macular degeneration (ARMD) appears preferable to observation based on recent Macular Photocoagulation Study (MPS) findings but is associated with decreased vision. The authors explored the use of vitreoretinal surgical techniques as an alternative method of eradicating subfoveal CNV. METHODS: After vitrectomy, a small retinotomy technique was used to extract or disconnect from the choroidal circulation subfoveal CNV in 58 eyes. There were 33 eyes with ARMD, 20 eyes with presumed ocular histoplasmosis, and 5 eyes with miscellaneous etiologies. Five eyes also received subfoveal RPE patches. RESULTS: With limited follow-up, significant improvement in vision (defined as 2 Snellen lines) was achieved in 7 of 22 eyes with ARMD CNV removal (1 eye 20/20), 0 of 4 eyes with ARMD CNV removal and RPE patches, and 1 of 7 eyes with ARMD CNV disconnection. Significant improvement was achieved in 6 of 16 eyes with presumed ocular histoplasmosis removal and 0 of 4 eyes with presumed ocular histoplasmosis CNV disconnection. In 5 eyes with miscellaneous CNV, 2 improved (20/20 and 20/40). CNV recurred in 29%. CONCLUSIONS: Some patients with subfoveal CNV appear to benefit from surgical removal. Only rarely do eyes with ARMD improve. Longer-term follow-up and refined case selection are required before this approach can be widely recommended.     

干性ARMD中视网膜色素上皮细胞的作用及损伤机制

年龄相关性黄斑变性(age-related macular degeneration,ARMD)是导致老年人中心视力不可逆丧失的主要原因。ARMD的典型特征是视网膜色素上皮(retinal pigment epithelium,RPE)和脉络膜毛细血管发生退行性改变及黄斑区出现玻璃膜疣。临床上ARMD分为两种亚型：非渗出型(干性或萎缩型)和渗出型(湿性或新生血管型)。该病的发生是年龄、环境、遗传、吸烟、氧化应激和心血管功能障碍等多种因素相互作用的结果。鉴于RPE细胞在ARMD发病中的重要作用,现以RPE细胞为重点,总结了蓝光、吸烟、氧化应激、脂褐素积累、慢性炎症和蛋白质稳态对干性ARMD发病的作用和可能机制,为认识和预防干性ARMD的发生提供新的帮助。     

Treatment of massive subretinal hematoma associated with age-related macular degeneration using vitrectomy with intentional giant tear

The purpose of this study was to report the surgical outcomes after creating a 120° intentional giant retinal tear for use in removing hemorrhage and subretinal proliferative tissue in patients with polypoidal choroidal vasculopathy (PCV) or age-related macular degeneration (ARMD). This study involved 12 eyes of 12 patients (10 eyes: PCV, 2 eyes: ARMD). After removal of the lens in phakic eyes, we performed a vitrectomy with artificial posterior vitreous detachment. Subsequently, a 120° intentional giant retinal tear was created in the temporal periphery, the retina was then turned, and the subretinal hemorrhage and proliferative tissue were removed. In order to preserve as much of the retinal pigment epithelium (RPE) as possible, we used a bimanual technique under direct visualization. After stretching the retina by use of perfluorocarbon liquid (PFCL), we performed endophotocoagulation around the tear followed by PFCL/silicone oil exchange. Except for 1 eye in which extensive loss of the RPE occurred, the fundus findings and the visual acuity (VA) improved in all patients. In addition, postoperative VA improved to ≥20/50 in 3 eyes in which the macular RPE was preserved. This surgical procedure is an effective treatment for PCV or ARMD patients with extensive subretinal hemorrhage and proliferative tissue.     

Amniotic membrane maintains the phenotype of rabbit retinal pigment epithelial cells in culture

The success of surgical removal of choroidal neovascularisation followed by transplantation of autologous retinal pigment epithelial cells (RPE) for age-related macular degeneration (ARMD) may be limited by damage in Bruch's membrane. We investigated whether amniotic membrane (AM) might be used as an alternative basement membrane-containing matrix to support RPE growth and differentiation. Primary RPE plastic cultures were established from freshly enucleated Dutch belted rabbit eyes in DMEM/F12 containing 0.1 mM Ca(++) and 10% dialysed FBS. Upon subconfluence, cells were subcultured at 5000-9000 cells cm(-2) in the above-mentioned culture medium on intact AM (iAM), epithelially denuded AM (dAM) or plastic. After confluence, the Ca(++) concentration in the medium was increased to 1.8 mm for 4 weeks. Growth and morphology were monitored by phase contrast microscopy, and the phenotype by immunostaining with antibodies against cytokeratin 18, tight junction protein ZO-1, and RPE65 protein, and by transepithelial resistance (TER) measurement. Immunostaining to cytokeratin 18 confirmed the epithelial origin of isolated cells in both primary culture and subcultures. Compared to plastic cultures, RPE increased pigmentation within 24 hr after seeding on AM, with iAM being more pronounced than dAM. RPE adopted a hexagonal epithelial phenotype with more organised pigmentation, strong expression of ZO-1 and RPE65, and a significantly higher TER 4 weeks after Ca(++) switch on dAM. Our results indicate that AM may be used as a basement membrane-containing matrix to maintain RPE phenotype in vitro, and may facilitate subsequent transplantation to treat ARMD.     

Fundus autofluorescence and development of geographic atrophy in age-related macular degeneration

PURPOSE: To describe the development of new and enlargement of preexisting atrophy confined to areas with abnormally high levels of in vivo autofluorescence in eyes with geographic atrophy (GA) associated with age-related macular degeneration (ARMD). METHODS: The spatial distribution and intensity of fundus autofluorescence as well as the spread of GA and occurrence of new GA was recorded over a period of 3 years in three patients with ARMD using a confocal scanning laser ophthalmoscope. RESULTS: A diffuse irregular increased autofluorescence at the posterior pole was recorded at baseline in the presence of unifocal or multifocal patches of geographic atrophy. Within these areas of elevated autofluorescence, new atrophic areas developed, and existing patches of atrophy enlarged during the review period, whereas this was not observed in areas with normal background autofluorescence. The total area of abnormal autofluorescence also showed enlargement over time. CONCLUSIONS: These preliminary findings suggest that areas of increased autofluorescence precede the development and enlargement of outer retinal atrophy in eyes with ARMD. Because the dominant fluorophores of fundus autofluorescence are part of lipofuscin granules of RPE cells, the observations indicate that excessive RPE lipofuscin accumulation may be of significance in the pathogenesis of GA associated with ARMD. With GA being a major cause for severe visual loss in ARMD, in vivo fundus autofluorescence recording over time may allow identification of prognostic determinants and may give important clues to the understanding of mechanisms of disease.     

Ultrastructural and immunocytochemical changes in retinal pigment epithelium, retinal glia, and fibroblasts in vitreous culture.

Retinal pigment epithelial (RPE) cells, retinal glial, and fibroblasts, three cell types believed to play a role in the pathogenesis of epiretinal membrane formation, were maintained in vitreous culture to determine the influence of vitreous on their ultrastructure and expression of cytokeratin, glial fibrillary acidic protein (GFAP), vimentin, and glutamine synthetase (GS). Using a highly sensitive, preembedding technique for the immunolocalization of these antigens at the ultrastructural level, most RPE cells were found to lose cytokeratin and vimentin within 1 day after seeding on irradiated vitreous. The percentage of keratin-positive cells then increased with time in culture. If the vitreous was placed on RPE cells cultured in monolayer instead of placing the cells on the vitreous, keratin and vimentin were expressed these intermediate filament proteins diminished with time. Glutamine synthetase was found in RPE cells grown in monolayer with or without a vitreous overlay, but not in RPE cells grown on the surface of vitreous. Retinal glial grown on vitreous showed a time-dependent decrease in the number of cells expressing GFAP and a corresponding increase in cells expressing vimentin or GS. Some fibroblasts in vitreous culture expressed vimentin but not the other antigens evaluated. A substantial number of cells in each culture did not stain positively for cytokeratin, GFAP, vimentin, or GS. All three cell types showed phenotypic diversity at the ultrastructural level with each cell type being capable of assuming the same morphologic appearance under certain conditions. These results demonstrate the phenotypic plasticity of RPE cells, retinal glia, and fibroblasts when grown in contact with vitreous and provide further evidence that neither ultrastructure, intermediate filament protein expression, nor the presence of GS is sufficient to determine the cell type of origin of cells in epiretinal membranes.     

Predictors of drusen reduction after subthreshold infrared (810 nm) diode laser macular grid photocoagulation for nonexudative age-related macular degeneration

PURPOSE: To determine the predictors of drusen reduction in eyes with nonexudative age-related macular degeneration (ARMD) treated with subthreshold infrared (810 nm) diode laser macular grid photocoagulation. Additionally, to determine the relationship of laser-induced drusen reduction and best-corrected visual acuity (BCVA) 18 months after laser treatment.DESIGN: Randomized controlled clinical trial.METHODS: Fifty patients (100 eyes) with bilateral nonexudative ARMD were enrolled at two centers. One eye of each patient was randomized to the observation; the other eye was treated with 48 subthreshold (invisible end point) applications of infrared (810 nm) diode laser in a macular grid pattern. The eyes that received subthreshold laser treatment were compared with the eyes that received no treatment. The baseline fundus characteristics (number, size, and distribution of drusen, as well as focal hyperpigmentation) from two macula areas (central 1500 micro diameter, pericentral 1500 micro ring area) on stereo color photographs, the number of laser-induced lesions, and the area of laser induced retinal pigment epithelial (RPE) lesions on fluorescein angiography 3 months after treatment were studied as predictors of major drusen reduction (> or = 50% drusen reduction from baseline) 18 months after laser treatment. BCVA at baseline and 18 months later was compared in observation eyes and in laser-treated eyes.RESULTS: Eighteen months after randomization, 24 (48%) of 50 eyes treated with subthreshold laser had major drusen reduction compared with three (6%) of 50 observation eyes (P =.00001). At 3 months post-treatment in laser-treated eyes with major drusen reduction, the mean number of laser-induced lesions on fluorescein angiography was 30.7 and the mean area of RPE change was 0.81 mm(2) compared with 14.8 laser-induced lesions and 0.35 mm(2) area of RPE change in eyes without major drusen reduction (P =.0001 and P =.0003, respectively). At baseline, fundus characteristics were not significantly different between observation eyes and laser-treated eyes or between the major drusen reduction group and the nonmajor drusen reduction group. At 18 months after treatment, BCVA was not significantly different in laser-treated eyes and in observation eyes.CONCLUSIONS: Subthreshold infrared (810 nm) diode laser macular grid photocoagulation in eyes with nonexudative ARMD significantly reduced drusen 18 months after laser treatment. Both the number of subthreshold laser lesions and the area of RPE changes visible on fluorescein angiography 3 months after treatment appeared to be predictors for major drusen reduction 18 months after treatment. However, it remains to be determined whether laser-induced drusen reduction is beneficial for visual acuity or reduces the incidence of choroidal neovascularization (CNV) in eyes with nonexudative ARMD.     

Is age-related macular degeneration associated with pinguecula or scleral plaque formation?

PURPOSE: To evaluate whether ocular changes indicating an increased exposure to UV irradiation are associated with the development of age-related macular degeneration (ARMD). METHODS: Using histology, we have investigated a possible association of ocular changes that might be attributed to actinic damage, namely pinguecula and scleral plaque, with findings of both atrophic and disciform ARMD. A total of 74 eyes, could be used for evaluation. RESULTS: Features of ARMD were present in 36 eyes (11 with disciform degeneration and 25 with an atrophic form). A pinguecula was identified in 36 eyes (small in 22 eyes, large in 14 eyes), and a scleral plaque was seen in 5 eyes. While scleral plaque showed an association with ARMD, there was no significant association between pinguecula and ARMD. CONCLUSIONS: Our results support the concept of solar radiation having an effect on the development of ARMD but also indicate that it is a multifactorial disease.     

Iris pigment epithelial cell translocation in exudative age-related macular degeneration

Background: This prospective, non-controlled pilot study investigates the practicability of IPE translocation and functional outcome in ARMD patients. Removal of submacular choroidal neovascularization (CNV) in age-related macular degeneration (ARMD) is usually associated with RPE damage and poor visual prognosis. Homologous RPE transplants fail to preserve macular function, possibly due to immune rejection. Instead of homologous RPE, we suggest translocating autologous iris pigment epithelium (IPE), building on earlier evidence from animal and in vitro investigations that IPE can substitute RPE functions in the experimental animal. Immunological cell rejection is avoided. Methods: Four eyes with well- defined and eight eyes with ill- defined subfoveal CNV were submitted to operation and followed up for a minimum of 6 months. IPE cells were harvested from a peripheral iridectomy. A vitrectomy was performed. Submacular membranes were removed, and isolated IPE cells were injected into the subretinal space. Examinations included ETDRS visual acuity, fluorescein angiography, and SLO microperimetry. Results: All patients underwent successful surgical removal of CNV and subretinal IPE injection. Compared to preoperative visual acuity (20/400–20/100) no significant change was observed after 6 months (20/320–16/80). A change of more than two ETDRS chart lines was defined as significant. One eye with preoperative ill-defined CNV developed a recurrence, leading to reduced visual acuity. In all patients, postoperative fluorescence angiography revealed early hyperfluorescence (window defect) in the surgically denuded area. Central fixation was demonstrated in 50% of eyes. Conclusions: Preliminary data suggests that IPE translocation in submacular surgery for ARMD can preserve but not improve preoperative visual acuity over 6 months. Functional results are promising compared to submacular membrane extraction alone and RPE transplantation. Continued research on improvement of IPE translocation seems justified. Received: 19 October 1999 Revised: 22 December 1999 Accepted: 16 February 2000     

Inflammation in dry age-related macular degeneration

PURPOSE: To summarize the current information regarding the role of immune and inflammatory response in the pathogenesis of dry age-related macular degeneration (ARMD). METHODS: A Pubmed search was conducted of the period January 1999 to 2005. Relevant information in the literature on the role of inflammation in early dry ARMD was reviewed. RESULTS: Some important evidence for inflammation in early ARMD consists in the isolation of immunoglobulins, complement proteins, cytokines and activated microglia, in retinal pigment epithelium (RPE) cells and drusen. Pivotal mechanisms in early ARMD include the accumulation of debris and proteins along the RPE surface, followed by immune-complex deposition and complement activation. In contrast, the role of other plasma enzymes such as kallikrein-kinin-bradykinin, the Hageman factor, peptides and coagulation proteins in drusen formation and ARMD has yet to be determined. CONCLUSION: A clear role for inflammatory mediators and cells has been established in recent years. Future studies should elucidate further mechanisms in ARMD development.     

Comparison with indocyanine green angiography and immunohistochemical study of choroidal neovascular membrane in age-related macular degeneration

PURPOSE: We classified choroidal neovascular membranes (CNMs) (48 eyes) in age-related macular degeneration (AMD) into four types using indocyanine green angiography. METHODS: Surgically extracted CNMs were examined immunohistochemically. Specimens were stained with glial fibrillary acidic protein (GFAP), von Willebrand factor, Ki-67 antigen, actin, vascular endothelial growth factor (VEGF), basic fibroblast growth factor (b-FGF), and transforming growth factor (TGF-beta 1). RESULTS: All types of CNM were positively stained with GFAP on the side opposite the retinal pigment epithelial (RPE) cells. This suggests the adherence of neurosensory retina to the CNM. Type I membranes which showed hyperfluorescence in the early and late phase of ICG angiography were significantly stained with Ki-67 antigen. CONCLUSION: These results indicate that CNMs in AMD are extracted with neurosensory retina and RPE cells during surgery. Type I membranes have a high capability for proliferation.     

Ultrastructural immunocytochemistry of subretinal neovascular membranes in age-related macular degeneration.

BACKGROUND: The authors studied various cellular and extracellular matrix components of subretinal neovascular membranes (SRNVM) from patients with age-related macular degeneration (ARMD). METHODS: Electron microscopic immunocytochemistry was used on the subfoveal neovascular membranes surgically removed from three patients with disciform lesions due to ARMD. FINDINGS: The SRNVMs always contained large "feeder" vessels along with many new capillaries in different stages of maturation. Capillaries were sparse and embedded in an abundant stroma. The majority of the nonvascular cells were either retinal pigment epithelial (RPE) cells or fibroblast-like cells. The RPE cells formed single or multiple layers on one side of the membranes. The stroma was composed mainly of collagen types I and IV and fibronectin, with small amounts of collagen types III, V, and VI. The absence of Bruch's membrane suggests that a splitting may occur between the RPE cells and Bruch's membrane with the new vessels growing into this cleft. A thickened layer of collagen type IV was often present under the RPE cells. The basement membranes of the newly formed capillaries were morphologically ill-defined, and contained substantial amounts of collagen type IV and fibronectin, but, unlike the basement membranes of normal capillaries, they lacked laminin or heparan sulfate proteoglycan. CONCLUSION: These results on the ultrastructural components of the SRNVMs may be useful in clarifying the nature of the disciform process in ARMD.     

Adenovirus mediated gene delivery of tissue inhibitor of metalloproteinases-3 induces death in retinal pigment epithelial cells.

BACKGROUND: Sorsby's fundus dystrophy (SFD) and age related macular degeneration (ARMD) are retinal diseases associated with a high level of accumulation of mutant and wild type TIMP-3, respectively, in Bruch's membrane. The pathogenic role of TIMP-3 in these diseases is uncertain, but causative mutations have been identified in the TIMP-3 gene of patients with SFD. Recent reports that TIMP-3 causes apoptosis in certain cell types and not in others prompted the authors to investigate whether TIMP-3 causes apoptosis in cultured retinal pigment epithelium (RPE) cells. METHODS: RPE and MCF-7 cells (as a positive control) were initially infected with replication deficient adenovirus, to overexpress beta-galactosidase (RAdLacZ) or TIMP-3 (RAdTIMP-3). TIMP-3 was detected by western blotting and ELISA. Cell viability was defined by cell counts. ISEL was used to investigate the mechanism of cell death. RESULTS: Cultured RPE cells produced small quantities of endogenous TIMP-3 and remained viable. However, overexpression of TIMP-3 caused a dose related death of RPE cells. The mechanism of cell death was apoptosis. CONCLUSION: The previously unreported finding of TIMP-3 induced apoptosis of RPE cells may account for some of the early features seen in SFD and ARMD.